[PATCH 1/2] power: supply: ltc2941: simplify Qlsb calculation

[PATCH 1/2] power: supply: ltc2941: simplify Qlsb calculation

[Michał Mirosław]

Replace two divisions with a subtraction+shift for a small code size
improvement and less brackets.

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
---
 drivers/power/supply/ltc2941-battery-gauge.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/power/supply/ltc2941-battery-gauge.c b/drivers/power/supply/ltc2941-battery-gauge.c
index 09f3e78af4e0..c0cbf4cd59ee 100644
--- a/drivers/power/supply/ltc2941-battery-gauge.c
+++ b/drivers/power/supply/ltc2941-battery-gauge.c
@@ -490,13 +490,13 @@ static int ltc294x_i2c_probe(struct i2c_client *client,
 	if (info->id == LTC2943_ID) {
 		if (prescaler_exp > LTC2943_MAX_PRESCALER_EXP)
 			prescaler_exp = LTC2943_MAX_PRESCALER_EXP;
-		info->Qlsb = ((340 * 50000) / r_sense) /
-				(4096 / (1 << (2*prescaler_exp)));
+		info->Qlsb = ((340 * 50000) / r_sense) >>
+			     (12 - 2*prescaler_exp);
 	} else {
 		if (prescaler_exp > LTC2941_MAX_PRESCALER_EXP)
 			prescaler_exp = LTC2941_MAX_PRESCALER_EXP;
-		info->Qlsb = ((85 * 50000) / r_sense) /
-				(128 / (1 << prescaler_exp));
+		info->Qlsb = ((85 * 50000) / r_sense) >>
+			     (7 - prescaler_exp);
 	}
 
 	/* Read status register to check for LTC2942 */
-- 
2.30.2

[PATCH 2/2] power: supply: ltc2941: clean up error messages

[Michał Mirosław]

Replace dev_err() with dev_err_probe() in probe() and extend register
access failure messages. dev_err()s in _reset() are removed as they
are redundant: register access wrappers already log the error.

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
---
 drivers/power/supply/ltc2941-battery-gauge.c | 53 ++++++++------------
 1 file changed, 20 insertions(+), 33 deletions(-)

diff --git a/drivers/power/supply/ltc2941-battery-gauge.c b/drivers/power/supply/ltc2941-battery-gauge.c
index c0cbf4cd59ee..657305214d68 100644
--- a/drivers/power/supply/ltc2941-battery-gauge.c
+++ b/drivers/power/supply/ltc2941-battery-gauge.c
@@ -112,7 +112,8 @@ static int ltc294x_read_regs(struct i2c_client *client,
 
 	ret = i2c_transfer(client->adapter, &msgs[0], 2);
 	if (ret < 0) {
-		dev_err(&client->dev, "ltc2941 read_reg failed!\n");
+		dev_err(&client->dev, "ltc2941 read_reg(0x%x[%d]) failed: %pe\n",
+			reg, num_regs, ERR_PTR(ret));
 		return ret;
 	}
 
@@ -130,7 +131,8 @@ static int ltc294x_write_regs(struct i2c_client *client,
 
 	ret = i2c_smbus_write_i2c_block_data(client, reg_start, num_regs, buf);
 	if (ret < 0) {
-		dev_err(&client->dev, "ltc2941 write_reg failed!\n");
+		dev_err(&client->dev, "ltc2941 write_reg(0x%x[%d]) failed: %pe\n",
+			reg, num_regs, ERR_PTR(ret));
 		return ret;
 	}
 
@@ -148,11 +150,8 @@ static int ltc294x_reset(const struct ltc294x_info *info, int prescaler_exp)
 
 	/* Read status and control registers */
 	ret = ltc294x_read_regs(info->client, LTC294X_REG_CONTROL, &value, 1);
-	if (ret < 0) {
-		dev_err(&info->client->dev,
-			"Could not read registers from device\n");
-		goto error_exit;
-	}
+	if (ret < 0)
+		return ret;
 
 	control = LTC294X_REG_CONTROL_PRESCALER_SET(prescaler_exp) |
 				LTC294X_REG_CONTROL_ALCC_CONFIG_DISABLED;
@@ -172,17 +171,11 @@ static int ltc294x_reset(const struct ltc294x_info *info, int prescaler_exp)
 	if (value != control) {
 		ret = ltc294x_write_regs(info->client,
 			LTC294X_REG_CONTROL, &control, 1);
-		if (ret < 0) {
-			dev_err(&info->client->dev,
-				"Could not write register\n");
-			goto error_exit;
-		}
+		if (ret < 0)
+			return ret;
 	}
 
 	return 0;
-
-error_exit:
-	return ret;
 }
 
 static int ltc294x_read_charge_register(const struct ltc294x_info *info,
@@ -472,11 +465,9 @@ static int ltc294x_i2c_probe(struct i2c_client *client,
 	/* r_sense can be negative, when sense+ is connected to the battery
 	 * instead of the sense-. This results in reversed measurements. */
 	ret = of_property_read_u32(np, "lltc,resistor-sense", &r_sense);
-	if (ret < 0) {
-		dev_err(&client->dev,
+	if (ret < 0)
+		return dev_err_probe(&client->dev, ret,
 			"Could not find lltc,resistor-sense in devicetree\n");
-		return ret;
-	}
 	info->r_sense = r_sense;
 
 	ret = of_property_read_u32(np, "lltc,prescaler-exponent",
@@ -502,11 +493,9 @@ static int ltc294x_i2c_probe(struct i2c_client *client,
 	/* Read status register to check for LTC2942 */
 	if (info->id == LTC2941_ID || info->id == LTC2942_ID) {
 		ret = ltc294x_read_regs(client, LTC294X_REG_STATUS, &status, 1);
-		if (ret < 0) {
-			dev_err(&client->dev,
+		if (ret < 0)
+			return dev_err_probe(&client->dev, ret,
 				"Could not read status register\n");
-			return ret;
-		}
 		if (status & LTC2941_REG_STATUS_CHIP_ID)
 			info->id = LTC2941_ID;
 		else
@@ -545,19 +534,17 @@ static int ltc294x_i2c_probe(struct i2c_client *client,
 		return ret;
 
 	ret = ltc294x_reset(info, prescaler_exp);
-	if (ret < 0) {
-		dev_err(&client->dev, "Communication with chip failed\n");
-		return ret;
-	}
+	if (ret < 0)
+		return dev_err_probe(&client->dev, ret,
+			"Communication with chip failed\n");
 
 	info->supply = devm_power_supply_register(&client->dev,
 						  &info->supply_desc, &psy_cfg);
-	if (IS_ERR(info->supply)) {
-		dev_err(&client->dev, "failed to register ltc2941\n");
-		return PTR_ERR(info->supply);
-	} else {
-		schedule_delayed_work(&info->work, LTC294X_WORK_DELAY * HZ);
-	}
+	if (IS_ERR(info->supply))
+		return dev_err_probe(&client->dev, PTR_ERR(info->supply),
+			"failed to register ltc2941\n");
+
+	schedule_delayed_work(&info->work, LTC294X_WORK_DELAY * HZ);
 
 	return 0;
 }
-- 
2.30.2

Re: [PATCH 1/2] power: supply: ltc2941: simplify Qlsb calculation

[Sebastian Reichel]

[-- Attachment #1: Type: text/plain, Size: 1428 bytes --]

Hi,

On Tue, Jan 11, 2022 at 03:32:40AM +0100, Michał Mirosław wrote:
> Replace two divisions with a subtraction+shift for a small code size
> improvement and less brackets.
> 
> Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
> ---

Thanks, queued.

-- Sebastian

>  drivers/power/supply/ltc2941-battery-gauge.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/power/supply/ltc2941-battery-gauge.c b/drivers/power/supply/ltc2941-battery-gauge.c
> index 09f3e78af4e0..c0cbf4cd59ee 100644
> --- a/drivers/power/supply/ltc2941-battery-gauge.c
> +++ b/drivers/power/supply/ltc2941-battery-gauge.c
> @@ -490,13 +490,13 @@ static int ltc294x_i2c_probe(struct i2c_client *client,
>  	if (info->id == LTC2943_ID) {
>  		if (prescaler_exp > LTC2943_MAX_PRESCALER_EXP)
>  			prescaler_exp = LTC2943_MAX_PRESCALER_EXP;
> -		info->Qlsb = ((340 * 50000) / r_sense) /
> -				(4096 / (1 << (2*prescaler_exp)));
> +		info->Qlsb = ((340 * 50000) / r_sense) >>
> +			     (12 - 2*prescaler_exp);
>  	} else {
>  		if (prescaler_exp > LTC2941_MAX_PRESCALER_EXP)
>  			prescaler_exp = LTC2941_MAX_PRESCALER_EXP;
> -		info->Qlsb = ((85 * 50000) / r_sense) /
> -				(128 / (1 << prescaler_exp));
> +		info->Qlsb = ((85 * 50000) / r_sense) >>
> +			     (7 - prescaler_exp);
>  	}
>  
>  	/* Read status register to check for LTC2942 */
> -- 
> 2.30.2
> 

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 833 bytes --]

Re: [PATCH 2/2] power: supply: ltc2941: clean up error messages

[Sebastian Reichel]

[-- Attachment #1: Type: text/plain, Size: 4663 bytes --]

Hi,

On Tue, Jan 11, 2022 at 03:32:41AM +0100, Michał Mirosław wrote:
> Replace dev_err() with dev_err_probe() in probe() and extend register
> access failure messages. dev_err()s in _reset() are removed as they
> are redundant: register access wrappers already log the error.
> 
> Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
> ---

Thanks, queued.

-- Sebastian

>  drivers/power/supply/ltc2941-battery-gauge.c | 53 ++++++++------------
>  1 file changed, 20 insertions(+), 33 deletions(-)
> 
> diff --git a/drivers/power/supply/ltc2941-battery-gauge.c b/drivers/power/supply/ltc2941-battery-gauge.c
> index c0cbf4cd59ee..657305214d68 100644
> --- a/drivers/power/supply/ltc2941-battery-gauge.c
> +++ b/drivers/power/supply/ltc2941-battery-gauge.c
> @@ -112,7 +112,8 @@ static int ltc294x_read_regs(struct i2c_client *client,
>  
>  	ret = i2c_transfer(client->adapter, &msgs[0], 2);
>  	if (ret < 0) {
> -		dev_err(&client->dev, "ltc2941 read_reg failed!\n");
> +		dev_err(&client->dev, "ltc2941 read_reg(0x%x[%d]) failed: %pe\n",
> +			reg, num_regs, ERR_PTR(ret));
>  		return ret;
>  	}
>  
> @@ -130,7 +131,8 @@ static int ltc294x_write_regs(struct i2c_client *client,
>  
>  	ret = i2c_smbus_write_i2c_block_data(client, reg_start, num_regs, buf);
>  	if (ret < 0) {
> -		dev_err(&client->dev, "ltc2941 write_reg failed!\n");
> +		dev_err(&client->dev, "ltc2941 write_reg(0x%x[%d]) failed: %pe\n",
> +			reg, num_regs, ERR_PTR(ret));
>  		return ret;
>  	}
>  
> @@ -148,11 +150,8 @@ static int ltc294x_reset(const struct ltc294x_info *info, int prescaler_exp)
>  
>  	/* Read status and control registers */
>  	ret = ltc294x_read_regs(info->client, LTC294X_REG_CONTROL, &value, 1);
> -	if (ret < 0) {
> -		dev_err(&info->client->dev,
> -			"Could not read registers from device\n");
> -		goto error_exit;
> -	}
> +	if (ret < 0)
> +		return ret;
>  
>  	control = LTC294X_REG_CONTROL_PRESCALER_SET(prescaler_exp) |
>  				LTC294X_REG_CONTROL_ALCC_CONFIG_DISABLED;
> @@ -172,17 +171,11 @@ static int ltc294x_reset(const struct ltc294x_info *info, int prescaler_exp)
>  	if (value != control) {
>  		ret = ltc294x_write_regs(info->client,
>  			LTC294X_REG_CONTROL, &control, 1);
> -		if (ret < 0) {
> -			dev_err(&info->client->dev,
> -				"Could not write register\n");
> -			goto error_exit;
> -		}
> +		if (ret < 0)
> +			return ret;
>  	}
>  
>  	return 0;
> -
> -error_exit:
> -	return ret;
>  }
>  
>  static int ltc294x_read_charge_register(const struct ltc294x_info *info,
> @@ -472,11 +465,9 @@ static int ltc294x_i2c_probe(struct i2c_client *client,
>  	/* r_sense can be negative, when sense+ is connected to the battery
>  	 * instead of the sense-. This results in reversed measurements. */
>  	ret = of_property_read_u32(np, "lltc,resistor-sense", &r_sense);
> -	if (ret < 0) {
> -		dev_err(&client->dev,
> +	if (ret < 0)
> +		return dev_err_probe(&client->dev, ret,
>  			"Could not find lltc,resistor-sense in devicetree\n");
> -		return ret;
> -	}
>  	info->r_sense = r_sense;
>  
>  	ret = of_property_read_u32(np, "lltc,prescaler-exponent",
> @@ -502,11 +493,9 @@ static int ltc294x_i2c_probe(struct i2c_client *client,
>  	/* Read status register to check for LTC2942 */
>  	if (info->id == LTC2941_ID || info->id == LTC2942_ID) {
>  		ret = ltc294x_read_regs(client, LTC294X_REG_STATUS, &status, 1);
> -		if (ret < 0) {
> -			dev_err(&client->dev,
> +		if (ret < 0)
> +			return dev_err_probe(&client->dev, ret,
>  				"Could not read status register\n");
> -			return ret;
> -		}
>  		if (status & LTC2941_REG_STATUS_CHIP_ID)
>  			info->id = LTC2941_ID;
>  		else
> @@ -545,19 +534,17 @@ static int ltc294x_i2c_probe(struct i2c_client *client,
>  		return ret;
>  
>  	ret = ltc294x_reset(info, prescaler_exp);
> -	if (ret < 0) {
> -		dev_err(&client->dev, "Communication with chip failed\n");
> -		return ret;
> -	}
> +	if (ret < 0)
> +		return dev_err_probe(&client->dev, ret,
> +			"Communication with chip failed\n");
>  
>  	info->supply = devm_power_supply_register(&client->dev,
>  						  &info->supply_desc, &psy_cfg);
> -	if (IS_ERR(info->supply)) {
> -		dev_err(&client->dev, "failed to register ltc2941\n");
> -		return PTR_ERR(info->supply);
> -	} else {
> -		schedule_delayed_work(&info->work, LTC294X_WORK_DELAY * HZ);
> -	}
> +	if (IS_ERR(info->supply))
> +		return dev_err_probe(&client->dev, PTR_ERR(info->supply),
> +			"failed to register ltc2941\n");
> +
> +	schedule_delayed_work(&info->work, LTC294X_WORK_DELAY * HZ);
>  
>  	return 0;
>  }
> -- 
> 2.30.2
> 

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 833 bytes --]